Semiconductor photonic crystals for optoelectronics

We present a number of designs for the integration of photonic crystals (PC) with active semiconductor devices. As a first step, the use of PC blocks as laser mirrors is demonstrated. Ridge-waveguide lasers with a length of <f>100 μm</f> and two PC mirrors achieve threshold currents below <f>8 mA</f>. In order to obtain single-mode operation, an intracavity PC mirror can be used, which effectively separates the laser into two coupled cavities. Lasing occurs where two modes of the cavities coincide, leading to single-mode operation with a side-mode suppression ratio (SMSR) of over <f>35 dB</f>. We also present two full PC devices: a single-mode laser with a coupled resonant cavity waveguide (CROW) and a tunable laser. The CROW device consists of a chain of 40 hexagonal cavities formed in a block of PC, with a total length of <f>140 μm</f>. Low threshold, single-mode operation with over <f>40 dB</f> SMSR is demonstrated. Coupled cavities are used for the tunable PC laser, which covers a tuning range of over <f>30 nm</f>. [Copyright &y& Elsevier]